Geographic Range

Stump-tailed macaques are native to southeast Asia. Their distribution includes China, India, Burma, West Malaysia, Thailand, Vietnam, eastern Bangladesh, and the Malay Peninsula. There is an introduced population in Tanaxpillo, Veracruz, Mexico, an island not inhabited by humans, where they live in conditions similar to their natural habitat in Asia. (Choudhury, 2002; Fooden, 1990)

Habitat

Stump-tailed macaques are found in subtropical evergreen forests below 1500 m and tropical evergreen rainforests between 1800 and 2500 m. They live in wet environments and are not found in dry forests. (Fooden, et al., 1985; Fooden, 1990)

Physical Description

Stump-tailed macaques, also known as bear macaques, have shaggy, dark brown hair covering them. They have hairless faces with red skin which darkens with sun exposure. Infants are born with white hair that darkens as they age. As they age, adult males and females show balding on the tops of their heads, much like human males, receding from the forehead towards the back of the skull. As in all other cercopithecines, they have cheek pouches that they use to store food when foraging. They are terrestrial quadrupedal movers. (Fooden, et al., 1985; Fooden, 1990)

Stump-tailed macaques have hairless tails that are shorter than other g.Macaca species. Tail length ranges from 3.2 to 69 mm. This species is sexually dimorphic in many aspects of their physiology. Males are larger, ranging from 9.9 to 10.2 kg and 517 to 650 mm in height whereas females are 7.5 to 9.1 kg and 485 to 585 mm in height. Males also have much larger canines, which they use for asserting dominance within their group. Like all cercopithecids, they have a dental formula of: 2/2, 1/1, 2/2, 3/3. (Choudhury, 2002; Fooden, 1990)

Reproduction

Stump-tailed macaques are promiscuous in their mating behavior. Dominance plays a big role in who gets to mate. High ranking males monopolize females in the group. However, lower ranking males have other strategies of obtaining mating opportunities. They hang back and mate with females when the dominant male is not watching. Often referred to as the "sneaker" male strategy. (Brereton, 1994; Fooden, 1990)

Both males and females initiate mating, though males tend to be more active when it comes to sexual behavior. Females make eye contact and present their perineal region (rump). Males approach females and sit next to them. Males chatter their teeth and grimace. When copulation is occurring, other group members often harass the pair. (Brereton, 1994; Cerda-Molina, et al., 2006)

In their native habitat, stump-tail macaques breed during the months of October and November. In captivity they don't reproduce on any seasonal schedule. Females have an offspring about every 2 years. The gestation period is 177 days. After birth, infants are nursed for 9 months. After weaning they are still dependent on their mother and other adults in the group and don't reach independence until about 1.5 years old. (Brereton, 1994; Estrada and Estrada, 1984)

Breeding occurs in October and November in wild, Feburary and March in the introduced Mexican population.

Average number of offspring

1

Average gestation period

177 days

Average weaning age

9 months

Average time to independence

18 months

Average age at sexual or reproductive maturity (female)

4 years

Range age at sexual or reproductive maturity (male)

4.5 to 5 years

The primary caregiver for young is the mother. She nurses, carries, and protects them. Additionally, all the females in the group care for the young of other females, especially if the mother is high ranking. Females carry, play with, protect, and groom the young. Alpha males will also help protect young and infants since there is a good chance they are their offspring. (Bauers and Hearn, 1994; Estrada and Estrada, 1984)

Stump-tailed macaques are more gentle with their young than other macaque species. Their is no threat of kidnapping from other group members, so mothers tend to be lenient with their young and give them independence in exploring the environment around them. (Bauers and Hearn, 1994; Estrada and Estrada, 1984)

Lifespan/Longevity

They can live up to 30 years in captivity. However, they tend to have shorter lifespans in the wild. (Choudhury, 2002)

Average lifespanStatus: captivity

30 years

Behavior

Stump-tailed macaques live in groups of up to 60 individuals consisting of adult males, females, and young. Females are philopatric and males leave after sexual maturity. They are hierarchical, with rank being reinforced through physical contact such as biting and slapping. However, compared to other macaque species, they are more peaceful and egalitarian in their social structure. When young males move into a new group they fight to establish rank in the hierarchy. After a disagreement or fight they have a specific ritual of reconciliation. The subordinate will present his rump to the dominant male, who will kiss or embrace the subordinate. The subordinate will respond by "lip smacking" or "teeth chattering". (Maestripieri, 1996)

Home Range

Territory size is unknown but is believed to be several square kilometers. During the day they travel 2 to 3 kilometers. They tend to travel less during the rainy season. After foraging during the day, they travel back to their sleeping sites in trees. (Choudhury, 2002; Fooden, 1990)

Communication and Perception

They communicate mostly visually and vocally. Common forms of visual communication are "teeth chattering", presenting one's rump to another individual, "lip smacking" and "barred teeth". When in heat, the females have swellings on their behind. This is a form of sexual communication, that they are receptive to mating.

Vocal communication often consists of "coo" which is used to stay in contact with other group members or when approaching another individual. They also use grunts when approaching another after fighting or if they are interested sexually. As mentioned before alpha males will "roar" to fend off predators.

Food Habits

Stump-tailed macaques have cheek pouches that, when filled, can hold a volume equal to that of their stomach. They forage starting in the morning through midday. They are omnivorous, but they eat mostly fruit. They also eat seeds, flowers, roots, leaves, and animals such as frogs, freshwater crabs, birds, and bird eggs.
They have also been known to raid corn crops and cultivated fruits. (Fooden, et al., 1985; Fooden, et al., 1985)

Ecosystem Roles

Economic Importance for Humans: Positive

Humans have used stump-tailed macaques for testing the anti-hairloss drug minoxidil also known as Rogaine. By testing on the macaques, researchers were able to produce a safe product for human use. (Uno, 1986)

Positive Impacts

research and education

Economic Importance for Humans: Negative

Stump-tailed macaques can be a nuisance for farmers by crop raiding. (Fooden, 1990)

Negative Impacts

crop pest

Conservation Status

On the IUCN list stum-tailed macaques are considered vulnerable. They are at risk for extinction in the near future. Their populations have decreased 20% in the last 10 years. There have already been instances of certain populations disappearing. Indian and Bangladesh populations haven't been seen since 1990. Habitat and hunting are the main causes and concerns for their conservation. They are also becoming more uncommon in Thailand and Malaysia.
Human induced habitat change is the primary cause of population decline. Urban and agricultural expansion threatens native habitats.
In India, where these macaques are legally protected, they have set aside areas of land for stump-tailed macaque conservation and are enforcing protection. (Choudhury, 2002)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Charlotte Erfurth (author), University of Oregon, Stephen Frost (editor, instructor), University of Oregon.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

diurnal

active during the day, 2. lasting for one day.

dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nomadic

generally wanders from place to place, usually within a well-defined range.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

threatened

The term is used in the 1994 IUCN Red List of Threatened Animals to refer collectively to species categorized as Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), or Insufficiently Known (K) and in the 1996 IUCN Red List of Threatened Animals to refer collectively to species categorized as Critically Endangered (CR), Endangered (EN), or Vulnerable (VU).

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

Disclaimer:
The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.